Corneal Disease

The cornea is the transparent tissue that covers the front of the eye. It transmits light to the interior of the eye allowing us to see clearly. Corneal disease is a condition that can cause clouding, distortion and eventually blindness. There are many types of corneal disease. The three major types are keratoconus, Fuchs' endothelial dystrophy and bullous keratopathy.

Conjunctivitis ("pink eye")

This term describes a group of inflammatory and often contagious diseases of the conjunctiva (the protective membrane that lines the eyelids and covers exposed areas of the sclera, or white of the eye). These diseases can be caused by a bacterial or viral infection, drug allergy, environmental irritants, or a contact lens product.

At its onset, pink eye is usually painless and does not adversely affect vision. The infection will come and go in most cases without requiring medical care. But for some forms of pink eye, such as epidemic keratoconjunctivitis, treatment will be needed. If treatment is delayed, the infection may worsen and cause corneal inflammation and a loss of vision. Depending on the type of pink eye that a person develops, treatment often consists of antibiotics and steroids.

Ocular Herpes

Herpes of the eye is a recurrent viral infection that affects an estimated 400,000 Americans with herpes. Although ocular herpes can result from the sexually transmitted herpes simplex II virus, it is usually caused by herpes simplex virus I (HSV I), the virus responsible for cold sores. In about 12 percent of those with ocular herpes, both eyes are involved.

Herpes Zoster (shingles)

This infection is produced by the varicella-zoster virus, the same virus that causes chicken pox. After an initial outbreak of chicken pox (often during childhood), the virus remains dormant within the nerve cells of the central nervous system. But in some people, the varicella-zoster virus will reactivate at some time during their lives. When this occurs, the virus travels down long nerve fibers and infects some part of the body, producing a blistering rash (shingles), fever, painful inflammations of the affected nerve fibers, and a general feeling of malaise.

Corneal Dystrophies

There are over 20 corneal dystrophies that affect all parts of the cornea. Some of the most common are:

• Keratoconus The disorder arises when the middle of the cornea thins and gradually bulges outward, forming a rounded cone shape. This abnormal curvature changes the cornea's refractive power, producing moderate to severe distortion (astigmatism) and blurriness (near- and farsightedness) of vision. These changes may also disrupt the normal, light-conducting arrangement of corneal protein, causing swelling and a sight-impairing scarring of the tissue.

• Fuch's Dystrophy Fuch's dystrophy is a slowly progressing disease that usually affects both eyes and is slightly more common in women than in men. Although doctors can often see early signs of Fuch's dystrophy in people in their 30s and 40s, the disease rarely affects vision until a person reaches their 50s and 60s.

• Lattice Dystrophy Although lattice dystrophy can occur at any time in life, the condition usually arises in children between the ages of 2 and 7. It is characterized by an accumulation of abnormal protein fibers (amyloid) throughout the middle and anterior stroma. However, the disease is NOT related to amyloidosis, a serious systemic disease.